0010268: Pre embark site information doesn't take elevation into effect when predicting an aquifer

Dwarf Fortress Bug Tracker - Dwarf Fortress

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Category

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Date Submitted

Last Update

0010268

Dwarf Fortress

Dwarf Mode -- Embark/Setup

public

2017-07-23 03:07

Reporter

PatrikLundell

Assigned To

Priority

normal

Severity

minor

Reproducibility

have not tried

Status

new

Resolution

open

Platform

Windows

OS Version

10.1

Product Version

0.43.05

Target Version

Fixed in Version

Summary

0010268: Pre embark site information doesn't take elevation into effect when predicting an aquifer

Description

DF doesn't seem to account for "soil erosion" due to high elevation when predicting if an aquifer is present a a high elevation embark. It seems that if the geo biome of the embark has aquifer supporting soil (or rock, but that's legitimate) in third level or below the presence of an aquifer is declared, ignoring that DF will "erode" the top soil levels at high elevation embarks.

In addition to this, one of my test sites was at an elevation of 141 (play elevation, not world gen elevation), which should allow for at most two levels of soil. However, the geo biome had a single 3 layer deep sand soil layer followed by non aquifer supporting rock. The pre embark indication claimed there should be an aquifer, but none was found despite there actually being all three layers of sand. A different embark site at a lower elevation but probably within the same geo biome did get an aquifer in the third sand level.

Steps To Reproduce

I've generated a PSV world with PSV elevations of 100, 120, 140, 160, 180, 200, 220, 240, 260, and 280 for most of the major biome types, setting the drainage to either 0 or 100. It looked like DF generated geo biomes with 4 soil single level layers throughout regardless of the parameters, with the exception of a single 3 level deep sand layer. Test embarks were mainly done where the elevation was 141-149 (play elevation).

Additional Information

Using the Phoebus tiles set, DFHack 0.43.05-r2, the 32 bit DF version with the Lazy Windoze Pack.